Last year, HBO premiered Luck, a horse racing drama that starred big name actors like Dustin Hoffman and Nick Nolte and was produced by acclaimed director Michael Mann. However, the series was mired in controversy, thanks to the deaths of horses. After the death of a third horse, the series was cancelled and HBO probably thought the drama was over.

But it’s not. The network and the American Humane Association were hit with a lawsuit Wednesday over an alleged cover-up.

Barbara Casey was a the former director of production for AHA and claims that after working for the company for 13 years, she was wrongfully terminated last year, before the show was cancelled in March. She also claims that HBO and series producer Stewart Productions covered up the allegations of abuse in the suit filed in Los Angeles Superior Court, according to The Hollywood Reporter.

Casey details the alleged abuse in the suit, claiming that she saw horses drugged and underweight or sick horses used during filming. She says the AHA observed the producers using the wrong identifications on the horses to use them in filming so their medical pasts couldn’t be tracked.

She adds that HBO and Stewart Productions pressured the AHA to allow them to violate AHA regulations.

“AHA bowed to political and financial pressure and refused to report the Production Defendants’ conduct to the authorities,” the suit states, notes Entertainment Weekly. “AHA terminated Plaintiff’s employment in order to prevent her from reporting the …violation of animal abuse.”

HBO has responded with a statement, which reads, “We took every precaution to ensure that our horses were treated humanely and with the utmost care, exceeding every safeguard of all protocols and guidelines required of the production. Barbara Casey was not an employee of HBO, and any questions regarding her employment should be directed to the AHA.”

As for AHA, the organization responsible for the “no animals were harmed” stamp at the end of countless films, has not commented on the suit.